多个DHT11的读书数问题
求教：我打算用两个DHT11同时测温，程序如下，但始终显示同一个传感器读数，请问怎么改程序会显示两个DHT11的读数，非常感谢您的回答！#include <dht11.h>
#include<LiquidCrystal.h>
#define DHT11_PIN 1
#define DHT11_PIN 2
byte read_dht11_dat()
{
byte i = 0;
byte result=0;
for(i=0; i< 8; i++){
while(!(PINC & _BV(DHT11_PIN)));// wait for 50us
delayMicroseconds(30);
if(PINC & _BV(DHT11_PIN))
result |=(1<<(7-i));
while((PINC & _BV(DHT11_PIN)));// wait '1' finish
}
return result;
}
LiquidCrystal lcd(8,9,4,5,6,7);
void setup()
{
Serial.begin(9600);
lcd.begin(16,2);
DDRC |= _BV(DHT11_PIN);
PORTC |= _BV(DHT11_PIN);
}
dht11 DHT11;
void loop()
{
byte dht11_dat;
byte dht11_in;
byte i;
// start condition
// 1. pull-down i/o pin from 18ms
PORTC &= ~_BV(DHT11_PIN);
delay(18);
PORTC |= _BV(DHT11_PIN);
delayMicroseconds(40);
DDRC &= ~_BV(DHT11_PIN);
delayMicroseconds(40);
dht11_in = PINC & _BV(DHT11_PIN);
if(dht11_in){
Serial.println("dht11 start condition 1 not met");
return;
}
delayMicroseconds(80);
dht11_in = PINC & _BV(DHT11_PIN);
if(!dht11_in){
Serial.println("dht11 start condition 2 not met");
return;
}
delayMicroseconds(80);
// now ready for data reception
for (i=0; i<5; i++)
dht11_dat = read_dht11_dat();
DDRC |= _BV(DHT11_PIN);
PORTC |= _BV(DHT11_PIN);
byte dht11_check_sum = dht11_dat+dht11_dat+dht11_dat+dht11_dat;
// check check_sum
if(dht11_dat!= dht11_check_sum)
{
Serial.println("DHT11 checksum error");
}
lcd.setCursor(0,0);
lcd.print("H");
lcd.print(":");
lcd.print(dht11_dat, DEC);
lcd.print(".");
lcd.print(dht11_dat, DEC);
lcd.print("%");
lcd.setCursor(0,1);
lcd.print("T");
lcd.print(":");
lcd.print(dht11_dat, DEC);
lcd.print(".");
lcd.print(dht11_dat, DEC);
lcd.print("C ");
lcd.setCursor(9,0);
lcd.print(dht11_dat, DEC);
lcd.print(".");
lcd.print(dht11_dat, DEC);
lcd.print("%");
lcd.setCursor(9,1);
lcd.print(dht11_dat, DEC);
lcd.print(".");
lcd.print(dht11_dat, DEC);
lcd.print("C");
delay(1000);
}
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